Dave denied that he ever blocked Rivers from his show, but the bad blood between Rivers, NBC and ‘The Tonight Show’ is well known. “It was all about the Carson mess,” Joan said. “It doesn’t matter, you move on.”

“The Carson mess” refers to Rivers’ falling out with her mentor, Johnny Carson, who Joan admits gave her her big break.

A frequent guest comedian on ‘The Tonight Show,’ Rivers eventually took over as the permanent guest host — until she decided to launch her own competitive talk show on Fox.

Rivers said she called Carson to tell him she was doing her own show, and he hung up on her twice and never spoke to her again.

Unfortunately, Joan Rivers’ late-night talk show was canned within a year. Her husband Edgar, who produced the show, committed suicide by overdosing on prescription medication just months after the show was canceled.

Twenty-one years later, ‘The Tonight Show’ has not welcomed her back on the show, despite Joan’s claims she’s been desperately beating down their door.